UNITED NATIONS (Reuters) - The United Nations estimates that
around 9.3 million people in Syria or about 40 percent of the
population need humanitarian assistance due to the country's
2-1/2-year civil war, the U.N. humanitarian office said on
Monday.

"The humanitarian situation in Syria continues to
deteriorate rapidly and inexorably," U.N. humanitarian chief
Valerie Amos told the U.N. Security Council behind closed doors,
according to her spokeswoman Amanda Pitt.

"The number of people we estimate to be in need of
humanitarian assistance in Syria has now risen to some 9.3
million," Pitt said, summarizing Amos' remarks to the 15-nation
council. "Of them, 6.5 million people are displaced from their
homes, within the country."

The population of Syria is around 23 million.

"Amos continues to press the council for their help and
influence over those parties who can ensure the protection of
civilians and civilian facilities; the safe passage of medical
personnel and supplies; the safe and unhindered delivery of
humanitarian assistance; and can facilitate progress in
expanding critical, life-saving relief operations," Pitt said.

Amos' plea to the council follows the Syrian government's
promise on Monday to ensure delivery of vaccinations and
humanitarian aid across the country, after an outbreak of polio
in the Northeast and warnings of malnutrition in areas under
military siege.

Twenty-two children in Deir al-Zor province bordering Iraq
were left paralyzed last month. The polio virus has been
confirmed so far in 10 of them, and experts say it could spread
quickly across the region.

Last month Amos demanded stronger action by the Security
Council to get desperately needed aid into Syria, where millions
of people in need have not received any help for almost a year.

Violence and excessive red tape have slowed aid delivery to
a trickle in Syria. More than 100,000 people have been killed in
the civil war and millions have fled the country. After months
of talks, the 15-member Security Council approved a non-binding
statement on Oct. 2 urging increased humanitarian access.

Amos has complained that that statement has had little
impact on the ground. Western diplomats say they would like the
council to adopt a legally binding resolution but worry Russia
would veto it.

Russia, a close ally of Syrian President Bashar al-Assad,
and China have vetoed three Security Council resolutions since
October 2011 that would have condemned the government and
threatened it with sanctions.